Fuse and renewable element therefor



March 27, 1934. P. COTE FUSE AND RENEWABLE ELEMENT THEREFOR Filed May 29, 1930 x a I...|||

Patented Mar. 27, 1934 FUSE AND RENEWABLE ELEMENT THEREFQR Paul Cote, Chicago, Ill., assignor to American Standard Fuse Corporation, Albert Lea, Minn., a corporation of Delaware Application May 29, 1930, Serial No. 456,983

2 Claims.

"Ihis invention relates broadly to an improvement in the construction of electrical fuses, and in a novel arrangement for renewable fusible elements of such devices.

One object of my invention is to provide a fuse of the conventional tubular type, in which the fusible elements thereof may be readily replaced, and without the use of tools.

Another object is to provide a fusible element for renewable fuses, having terminal portions of a different material than the fusible element and which are made integrally with said element.

A further object is to provide a fuse of the class described, in which actual contact between the renewable fuse element and the fuse terminals is not affected by the surface resistance of the metallic alloy of Which said element is made.

A still further object is to provide a general construction which will permit the use of my novel fusible element, in tubular fuses of either the blade or ferrule contact type.

Other and further objects and advantages of my invention will appear as the specification progresses, and the novel features will be particularly pointed out in the appended claims.

In the drawing, Figure 1 is a view showing a general construction of one form of my improvement, as applied to blade type fuses. Figure 2 is a vertical cross-section of the fuse shown in Figure 1. Figure 3 is an end View of said fuse. Figure 4 is a sectional view taken along line 4 4 of Figure 2. Figure 5 is a similar View taken along line 5-5 of Figure 2. Figure 6 is another sectional view taken along line 6 6 of Figure 2. Figure 7 is a fragmentary sectional View disclosing the application of my improvement to ferrule contact fuses. Figure 8 is an upper end view of Figure '7, and Figure 9 is a sectional showing taken along line 9 9 of Figure 7. Similar parts in all the views are indicated by like reference numerals.

A tubular housing 1 made of suitable insulating material, such as fibre or bakelite, has fastened into the opposite ends thereof, electro conductive sleeves 2, by means of rivets 3. Said sleeves are provided with shoulders 4 adjacent to the ends of the tube 1 and the other ends of the respective sleeves are provided with an additional shoulder 5. The distance from shoulders 5 to the end of the respective sleeves is provided with external threads, being adapted to receive caps 7 which caps are provided with corresponding internal threads. To facilitate turning the caps they are provided with a knurled external surface 8.

The fusible element 9 (Figures 2 and '7) comprises a strip of any suitable metallic alloy or material commonly known and employed for fuse elements, and the ends of said strip are provided with contact members. Said contact members are disc-shaped metal pieces, preferably of brass. The ends of fuse element 9 fit into slots 9a of the contact members and are soldered therein in order to improve the electrical conductivity therebetween. IIhe member 10, while similar in shape to member 1l, is smaller than the latter, 65 and preferably of such diameter as will permit the same to pass freely through the sleeves 2. Said contact members are provided with enlarged head portions 10a and 11a respectively, so that while the head portion of member 10 will permit 70 the latter to be inserted through the sleeves 2, the larger head portion 11a cannot pass through said sleeves, since the latter are of smaller internal diameter than portion 11a.

It will be noted that the uppermost of the I5 sleeves 2 has pivotally mounted thereto by means of pivots l2 a pair of semi-ringshaped retaining members 13, which are made of an electro conductive material, such as brass.

In the blade type construction a pair of cop- 8 0 per blades 14 is provided. Said blades are fastened in perpendicular relation to metal Washers 15, and the innermost ends 14 of said blades extend a short distance beyond said washers. The blades may be fastened to said washers by means of solder, as shown at S.

The disc portion of the screw caps 7 have large openings '7' through which the blades 14 protrude, and the latter are provided with ears 142, which at all times prevent the blades from passing through and becoming separated from the caps 7. This feature prevents the individual parts from becoming lost or assembled in their wrong order.

When the fuse element 9 blows the remaining 95 portions thereof, including contact members 10 and 1l, may be removed by unscrewing and removing the caps 7. At this point the contact members will, by virtue of their own weight, drop out from the respective ends of the device. In order to renew the fuse a new element 9, with contacts 10 and 11 fastened thereon, may be inserted into the casing by rst swinging the retaining members 13 about their pivotal supports 105 to the position shown by the dotted lines in Figure 4; and thereafter inserting the renewable element by rst thrusting the smaller member 10 longitudinally through said casing. Then the members 13 should be closed, as shown in Figure 110 2, thereby preventing the smaller contact member (10) from being pushed back into the casing. After this is done the caps 7 may be screwed tightly on to their respective supporting sleeves 2, and a firm electrical contact of large area will thus be established between the blades 1,4 and the element 9. v

Since fuses of the blade type are generally fastened into spring contact jaws, it is necessary that the blades 14 be fastened into alignment with one another; that is, they must be moved rotatively until they both lie inthe same plane. For this purpose I provide slots extending diametrically across head portions 10a and 11a; said slots being of suiicient dimensions to accommodate the innermost ends 14 of the blades.

Where connection is made directly to the end caps of fuses, as in the type shown in Figures 7, 8 and 9., the aforementioned blades are not neces,- sary and, therefore, the caps. 7 may be screwed on so that they. make. direct connections with the fuse contacts 10 and 11 respectively. In this latter type vent holes o. are provided in the caps in order to permit the gases and metallic vapors tlc?l escape from within the chamber when the fuse blows. `It will be manifest from Figure 'l that said Vent holes are in central registration with the'rdiarnetrical slots of the head portions 10d.y and 11a, so, that the gases or vapors may pass through the slots, and escape through the holes.

It is obvious that numerous variations may be made in the details set forth, without departing from the spirit and scope of the invention as defined in the claims.

I claim:

l. In a fuse, an insulating tube, tubular terminal portions fastened to the ends thereof, an element within said tube comprising a fusible conductor having disc-shaped contact members soldered to the ends thereof, one of said members being of smaller diameter than the other member, said smallest member being slidable longitudinally through said casing and a retaining shoulder on said largest member for pre- Venting the latter from entering said casing.

2. In a renewable fuse, a hollow tubular casing, a fusible element having disc-shaped metal terminals integral with its ends, said terminals substantially closing the end apertures of the casing, one terminal having a greater diameter than the aperture at one end of the casing, the other terminal having a smaller diameter than both said apertures, movable means secured to one end of the casing for engaging the inner face of the smaller terminal, and metal contact caps enclosing both ends, of the casing for clamping said terminals in place and for establishing a circuit through the entire fuse.

' PAUL COTE. 

